Frequency-Adaptive Damper Piston for Comfort and Road Holding
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Solution Overview
Problem
Conventional damper assemblies face a compromise between performance, safety, and driving comfort, with passive shock absorbers being expensive, complex, and requiring additional sensors and control algorithms, while frequency-dependent valves increase dead-length and require costly drilling, leading to weaknesses and contamination.
Innovation Solution
A damper assembly with a frequency-adaptive orifice (FAO) valve assembly that includes a piston with an FAO passage and a tappet to selectively block or allow fluid flow based on excitation frequency, reducing damping forces during high-frequency events for improved comfort and road holding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If conventional passive shock absorber valves are used, then the structure is simple, but the performance compromise between safety and driving comfort is poor
Solution Approach 1:
The valve assembly transitions from a static passive valve to a dynamic frequency-adaptive system. The tappet and cover member move relative to each other based on excitation frequency, automatically adjusting damping characteristics without requiring external sensors or control systems. This dynamic adaptation resolves the contradiction by providing active-like performance through passive mechanical means.
Solution Approach 2:
The system changes the damping parameter dynamically based on excitation frequency. At low frequencies, the valve provides high damping forces for body motion control, while at high frequencies, it reduces damping forces for vibration isolation. This parameter adaptation enables the valve to optimize both safety and comfort performance simultaneously.
2Reliability
If frequency-dependent valves are added as add-ons to existing damper design, then damping force reduction for high frequency events is achieved, but the dead-length of the damper is significantly increased
Solution Approach 1:
The frequency-adaptive valve assembly is nested within the existing damper piston structure. The tappet, cover member, and orifice are integrated into the piston body, utilizing the existing internal volume and structural space. This nesting approach enables frequency-dependent damping functionality without significantly increasing the overall damper length.
Solution Approach 2:
Instead of extending the damper length axially to accommodate frequency-dependent valves, the invention utilizes the radial and circumferential dimensions within the piston. The FAO passage and cover member are arranged in a configuration that exploits the cross-sectional area of the piston, thereby achieving frequency adaptation without increasing the damper's axial dead-length.
3Adaptability or versatility
If additional intersecting bypass holes are drilled in existing dampers, then frequency-dependent damping is achieved, but manufacturing cost increases and structural strength is weakened
Solution Approach 1:
The frequency-adaptive functionality is segmented into a separate valve assembly (tappet, cover member, and FAO passage) that can be independently manufactured and then assembled into the piston. This segmentation eliminates the need for complex intersecting bypass holes drilled through the valve tenon, preserving structural strength while achieving frequency-dependent damping capability.
Solution Approach 2:
The FAO passage is pre-formed in the piston body or valve assembly components during manufacturing, rather than requiring post-manufacturing drilling of intersecting holes. The cover member is pre-configured to selectively cover this passage based on excitation frequency, enabling the frequency-dependent damping function without compromising the structural integrity of the valve tenon through additional drilling operations.
4Adaptability or versatility
If additional intersecting bypass holes are drilled, then frequency-dependent valve functionality is achieved, but manufacturing cost and contamination risk increase
Solution Approach 1:
The frequency-adaptive valve assembly is designed to be pre-assembled with the FAO passage and cover member in place before final piston assembly. This preliminary configuration eliminates the need for costly and contamination-prone post-manufacturing drilling operations, reducing both manufacturing cost and the risk of contaminant introduction into the hydraulic system.
Solution Approach 2:
The frequency-dependent valve functionality is extracted as a separate, modular assembly that can be manufactured and tested independently before integration into the piston. This extraction approach simplifies the manufacturing process by avoiding complex intersecting hole drilling in the final assembly, thereby reducing cost and contamination risk while maintaining the desired functionality.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The FAO valve assembly effectively adjusts damping forces based on frequency, enhancing comfort and road holding without additional sensors or complex control systems, while maintaining structural integrity and reducing manufacturing costs.
Implementation Method 1
a tappet configured to translate relative to the body to bias the FAO cover member to selectively cover the FAO passage in response to the application of the low-frequency excitation
Data Source
AI summary
A damper assembly includes a housing having a tubular shape defining a main chamber extending along a center axis. A piston is movable along the center axis and divides the main chamber into a compression chamber and a rebound chamber. The piston includes a piston body defining a frequency-adaptive orifice (FAO) passage providing fluid communication between the compression chamber and the rebound chamber. The piston includes an FAO valve assembly having an FAO cover member configured to block fluid flow therethrough in response to application of a low-frequency excitation, and allowing fluid flow through the FAO passage in response to application of a high-frequency excitation. The FAO valve assembly also includes a tappet configured to translate relative to the piston body to bias the FAO cover member to selectively cover the FAO passage in response to the application of the low-frequency excitation.